Mixing machine



Oct. 22, 1946. 2,409,646

MIXING MACHINE Filed May 26, 1945 .5 Sheets- Sheet l .50 FIG. 1 0 72 l 74 6O 73 A 5 J5 J INVENTOR Jingle? \ja flag, ,OM

.14- 22 Z3 Z6 ATTORNEY Oct. 22, 1946.

H. J. SEAMAN 2,409,646

' MIXING MACHINE v Filed May 26, 1945 s Sheets-Sheet 2 INVENTOR HARRYJ. SEA AN ATTORNEY Patented Oct. 22, 1946 PATENT OFFICE MIXING MACHINE Harry J. Seaman, Milwaukee, Wis. Application May 26, 1943, Serial No. 488,539

The present invention relates to mixing machines adapted for preparing roadmaterials' and the like.

An object of the invention is to provide an improved machine for effecting a thorough and expeditious mixing and pulverizing of road-building aggregates and for uniformly incorporating therewith a stabilizing material such as a bituminous binder.

Another object is to provide a mixing machine having simple but effective means for permitting yielding of a mixing rotor thereof upon encountering obstructions in the material or excessively heavy loads.

A further object is to provide a mixing machine having simple and durable means for driving a plurality of mixing rotors.

A still further object is to provide a mixing machine which can be inexpensively manufactured, which is reliable in operation, and which will permit ready access to operating parts.

The invention further consists in the several features hereinafter described and claimed.

3 Claims. (Cl. 259-6) In the accompanying drawings, illustrating certain embodiments of the invention,

Fig. 1 is a side elevation of one form of mixing machine constructed in accordance with the invention;

Fig. 2 is a longitudinal sectional elevation of the machine;

Fig. 3 is a transverse sectional view, taken generally along the line 3-3 of Fig. 2;

' Fig. 4 is a detail top view of a mixing rotor and its mounting;

Fig. 5 is a view similar to Fig. 2, but showing a modified form of mixing machine;

Fig. 6 is a transverse sectional-elevation of the machine of Fig. 5, taken generally along the line 6"Ei of Fig. 5, and

Fig. 7 is a sectional View taken generally along the line l'! of Fig. 5.

Referring to the construction shown in Figs. 1 to i, ii] designates a frame which includes parallel inclined stringers H, l2, and I3 at its upper portion and further includes horizontal bottom skids l4 permitting the frame to be detachably carried by a suitable wheeled vehicle such as a trailer I5. At one end of the frame is mounted a power unit l6, preferably of the type including an internal combustion engine, which transmits power through a horizontal drive shaft H extending longitudinally of the frame. The shaft IT is enclosed in a tubular member [8 having a gear housing [9 at the end distant from the power unit, the other end of the tubular member being swingably mounted. on a transverse horizontal pivot 20 adjacent to the power unit, so as to permit the tubular member and attached gear housing to be swung in a vertical plane. The end of the shaft ll within the gear housing carries a bevel pinion 2 I, Fig. 2, which meshes with a bevel gear 22 on a transverse horizontal shaft 23 journalled in the gear housing. A sprocket wheel 24 is carried on the shaft 23 exterior to the gear housing for driving mechanism hereinafter described. The swingably mounted gear housing is retained at a selected elevation by a bolt 25 engaging a supporting plate 26 on the frame, the plate having a series of openings 21 for selectively receiving the bolt.

A conveyer 28 of the belt or apron type extends between the inclined frame stringers II and I2 and comprises a series of overlapping cross slats 29 secured to a pair of side chains 39. The chains pass over sprocket wheels 3! and 32 carried on respective horizontal shafts 33 and 34 which are journalled in self-aligning bearings 35 and 35 secured to the underside of the stringers H and I2 near the opposite ends of these stringers. The conveyer has a straight, inclined upper run forming an elevator, the side chains 39 of this portion of the conveyer riding on trackways 31 secured to the frame. The lower conveyer shaft 34 is adjustable to take up wear and slack in the conveyer, The upper conveyer shaft 33 has a sprocket wheel 38, Fig. 3, secured to one end thereof and connected by a chain 39 to a small sprocket wheel Ml on a shaft 4|, Fig. 2, the chain drive being enclosed in a housing 42. The shaft 4| is intermediate and parallel to the conveyer shafts 33 and 34 and is journalled in self-aligning bearings 43 secured to the frame stringers II and I2. A large sprocket wheel M, Figs. 1 and 3, is secured to the end of the shaft 4| distant from the sprocket wheel 40.

Extending transversely above the upper run of the conveyer are two power-driven mixing rotors 45 and 45, the axes of rotation of the rotors being approximately horizontal and being spaced longitudinally of the stringers and arranged at opposite sides of the vertical plane of the shaft 4|. Each rotor comprises a tubular shaft 41 having detachably secured thereon several rows of resilient hooked tines or teeth 48, the teeth being hooked in the direction of rotation, and the teeth at the underside of the rotors moving in the same direction as the upper run of the conveyer. A spool-shaped bushing 49, Fig. 3, is pressed and welded into an end of the tubular shaft v l! and is rigidly carried. on an aligned 3 shaft 50. The shaft 50 of each rotor is journalled in self-aligning anti-friction bearings secured to the opposite parallel bars 52 of a tiltably mounted rectangular bearing frame or support 53, Figs. 3 and 4. The outer side bar of the bearing frame 53 carries a pivot rod 54 extending transversely of the rotor shaft and parallel to the frame stringers l3, the rod being journalled at opposite ends in spaced pillars 55 upstanding from the stringer 13. The normal horizontal position of the rotor is determined by a post 56, Fig. 3, upstanding from the stringer l2, the post 56 having an adjustable jack screw 5? on which the rectangular bearing frame normally rests.

The two mixing rotors 45 and 436 are enclosed by an elongated inclined hood-forming casing 58 which extends above the upper run of the conveyer and is supported by the frame stringers II and i2. At its lower end the casing 58 forms a hopper 59 for the road material to be mixed, the side of the hopper adjacent to the rotor 45 being formed by an inclined fiat gate Eli which is slidable in the casing to adjust the thickness of the bed of material moving upwardly along the conveyer. The adjustment of the gate is effected by a rack-and-pinion connection iii, Fig. 8, the pinion shaft having a handwheel 62, Fig. 3, accessible at the side of the casing 58 supported by the stringer I l.

The lower edges of the side walls of the casing 58 have outturned longitudinal flanges 83, Fig. 3, extending above and along the opposite side portions of the upper run of the conveyor. The casing side wall adjacent to the stringer l 2 is slotted to receive the rotor shafts 53, the slotted portions being closed by detachable slotted cover plates 64. The other casing side wall is provided with rectangular openings 55 for access to the rotors these openings being normally closed by removable panels 66 which are adjacent to the free ends of the rotors. A transverse balile plate 61, Fig. 2, extends between the side walls of the casing 58 at a region about midway between the mixing rotors 55 and 46. Extending transversely in the casing near the upper portion thereof are spray pipes 58, 69, and i9 adapted for pressure spraying a suitable liquid binder, such as bituminous oil, onto the material being mixed. The spray pipe 58 is disposed in the casing chamber having the rotor 35, and the spray pipes 69 and 10 are in the chamber having the rotor 46. Some or all of the spray pipes are provided with shield plates H. The spray pipes are connected to a supply header 12, extending along one side of the casing 58, each spray pipe having a valve 13, Figs. 1 and 3. The casing 58 has a vertical end wall 14 spaced from the discharge end of the conveyer to permit the downward passage of the material.

The mixed material moving over the upper end of the conveyer drops into a mixing chamber '15, Figs, 2 and 3, constituting an extension of the casing 58, the chamber 75 having a concave bottom wall l6 and an angular cover member I'lforming a top wall 18 and a side wall 79 and presenting a downwardly opening discharge passage 85 between the outer edge of the concave bottom wall and the lower edge of the side wall 79. The cover member 1'! is pivoted at 8! for access to the chamber '55. A mixing rotor 82 extends horizontally in the chamber in parallel relation to the other mixing rotors, the axis of the rotor 82 being below the level of the conveyer shaft 33. The rotor 82. is generally similar to rotors and 46 except that it has aligned plane of the sprocket wheels 24 and 44.

4 shafts 83 at both ends journalled in self-aligning bearings 84 secured to thbe machine frame. One of the rotor shafts 83 carries a sprocket Wheel 85 which is connected by a chain 86 to a similar sprocket wheel 81 on the shaft of the mixing rotor 46.

The shafts 50 of the first and second stage mixing rotors 45 and 46 are each provided with a sprocket wheel 88 arranged close to the vertical plane of the pivot rods 54 for the tiltable rotor mountings and disposed in the vertical An endless driving chain 39, Fig. 1, is trained over the sprocket wheels 24, 44 and 33, thereby driving the conveyer and also the first and second stage mixing rotors. The chain 89 has a reentrant portion extending over the sprocket wheel 44, thus increasing the arc of chain engagement on the sprocket wheel 88 of the second stage mixing rotor 16. The tension of the driving chain '89 is adjusted by raising or lowering the pivotally mounted gear housing iii. The final mixing rotor 82 is driven by the chain 86 from the shaft of the second stage mixing rotor.

In operation, loose road material or aggregate, such as crushed stone, gravel, or sand, or mixtures thereof, is placed inthe hopper 59. From the hopper the material passes upwardly along the inclined upper run of the conveyor 28, the depth of the bed of material being regulated by the gate GB. The conveyer is driven at a suitable low rate of speed by the reduction gearing comprising the large sprocketwheel 44 at one end of the shaft 4!, and the chain drive at the other end of this shaft. As the material on the conveyer reaches the zone of action of the rotor 45, it is coated with the liquid bituminous binder sprayed onto the material from the pipe 68 and is mixed and pulverized by the rotor, the material being thrown about by the rotor teeth against the walls of the rotor chamber and being in suspension during the application of the binder. In a similar manner, the material is fur-- ther mixed and bituminated by the second stage rotor 46, and thereafter drops over the upper end '1 of the rotor teeth. The thoroughly mixed bituminated material is gradually discharged through the passage as indicated by the arrow in Fig. 2. The finished material may fall directly onto a road bed or into vehicles for further transport.

The first and second stage mixing rotors are each tiltably mounted and are capable of yielding upwardly when encountering excessive resistance, as indicated by broken lines in Fig. 3, thus avoiding damage to the mechanism by hard lumps or foreign objects in the material or by excessively heavy feeding. At the lower portions of their travel, the outer ends or tips of the teeth of the rotors 45 and 46 are normally spaced a short distance above the upper run of the belt conveyer, and this spacing can be readily adjusted by the jack screws 5i, so as to position the rotors during assembly and to compensate for subsequent wear on the rotor teeth.

The modified form of mixing machine shown in Figs. 5 to 7 includes a suitably driven final mixing rotor I82 similar to the rotor 82 of the machine of Figs. 1 to 4 but having its horizontal axis arranged transversely of the axes of the first and second stage rotors. In the modified machine, the frame Hi} supports a rotor casing I58 the front end wall [14 of which extends downward to form the end wall of a mixing chamber I15 for the rotor 182. The side walls of the casing I58 have portions which slope and converge downwardly to form walls of the chamber I15, as seen in Fig. 6, one of these walls merging into a concave bottom wall H6 of the chamber. The mixing chamber also has an angular cover member IT! similar to the cover member 11 of the machine of Figs. 1 to 4, and forming with an edge of the concave bottom wall a downwardly directed discharge passage 180. The mixing rotor 82 has shaft extensions I83 journalled in bearings I84 on the frame H0, one of the shaft extensions having a sprocket wheel I855.

The final mixing rotor is so located that the stream of material dropping from the conveyer will be more or less centered with respect to the length of the rotor, and a large part of the material will fall into the path of the rotor teeth. In passing from the upper end of the conveyer to the final mixing rotor the material will have a crosswise component of travel which will tend to improve the mixing action.

The side walls of the casing I58 are here shown to be provided with deflectors 19H adjacent to the upper run of the conveyer and in advance of the first and second stage mixing rotors 45 and 46, so as to urge the bed of material on the conveyer away from these side walls and into the path of the mixing teeth on the rotors.-

The machine of Figs. 5 to 7 is otherwise similar to that of Figs. 1 to 4 and operates in substantially the same manner.

What I claim as new and desire to secure by Letters Patent is:

1. In a mixing machine, the combination of an endless belt conveyer having an upper run for supporting thereon loose material to be mixed and for carrying the material therealong, a mixing rotor disposed transversely over said conveyer run for operating on the material, a casing extending over said rotor, means for supporting said rotor from one end thereof and having a pivotal axis extending transversely of the rotor axis to permit upward tilting of said rotor when encountering excessive resistance to rotation, and means for driving said rotor including a sprocket wheel on said rotor adjacent to the vertical plane of the axis of tilt.

2. In a mixing machine, the combination of an endless belt conveyer having an upper run for supporting thereon loose material to be mixed and for carrying the material therealong, a powerdriven mixing rotor disposed transversely over said conveyer run for operating on the material, a casing extending over said rotor and having opposite side walls with edge portions adjacent to said run, means for supporting and driving said rotor at one end thereof, the side wall of said casing adjacent to the free end of said rotor having an aperture for access to said rotor, and means for normally closing said aperture.

3. In a mixing machine, the combination of an endless belt conveyer having an upper run for sup-porting thereon loose material to be mixed and for carrying the material therealong, a powerdriven mixing rotor disposed transversely over said conveyer run for operating on the material, a casing extending over said rotor, a support at one end of said rotor having axially spaced bearings for carrying said rotor, means for tiltably mounting said support to permit upward displacement of said rotor when encountering excessive resistance to rotation, and stop means for determining the normal position of said tiltable rotor-carrying support.

HARRY J. SEAMAN. 

